Make `nvm ls-remote` return nvm_ls_remote's exit code.
Making sure fast alias tests do their own teardown.
Improving "nvm alias" tests to test for all cases.
Adding a failing test: `nvm ls 0.0.x` includes `v0.0.xy`
nvm_ls: format the version immediately, so that `nvm ls 0.0.1` doesn't return `nvm ls 0.0.10`